171 research outputs found
Bronchoalveolar lavage cytological alveolar damage in patients with severe pneumonia
INTRODUCTION: Histological examination of lung specimens from patients with pneumonia shows the presence of desquamated pneumocytes and erythrophages. We hypothesized that these modifications should also be present in bronchoalveolar lavage fluid (BAL) from patients with hospital-acquired pneumonia. METHODS: We conducted a prospective study in mechanically ventilated patients with clinical suspicion of pneumonia. Patients were classified as having hospital-acquired pneumonia or not, in accordance with the quantitative microbiological cultures of respiratory tract specimens. A group of severe community-acquired pneumonias requiring mechanical ventilation during the same period was used for comparison. A specimen of BAL (20 ml) was taken for cytological analysis. A semiquantitative analysis of the dominant leukocyte population, the presence of erythrophages/siderophages and desquamated type II pneumocytes was performed. RESULTS: In patients with confirmed hospital-acquired pneumonia, we found that 13 out of 39 patients (33.3%) had erythrophages/siderophages in BAL, 18 (46.2%) had desquamated pneumocytes and 8 (20.5%) fulfilled both criteria. Among the patients with community-acquired pneumonia, 7 out of 15 (46.7%) had erythrophages/siderophages and 6 (40%) had desquamated pneumocytes on BAL cytology. Only four (26.7%) fulfilled both criteria. No patient without hospital-acquired pneumonia had erythrophages/siderophages and only 3 out of 18 (16.7%) had desquamated pneumocytes on BAL cytology. CONCLUSION: Cytological analysis of BAL from patients with pneumonia (either community-acquired or hospital-acquired) shows elements of cytological alveolar damage as hemorrhage and desquamated type II pneumocytes much more frequently than in BAL from patients without pneumonia. These elements had a high specificity for an infectious cause of pulmonary infiltrates but low specificity. These lesions could serve as an adjunct to diagnosis in patients suspected of having ventilator-associated pneumonia
Statistics of non-linear stochastic dynamical systems under L\'evy noises by a convolution quadrature approach
This paper describes a novel numerical approach to find the statistics of the
non-stationary response of scalar non-linear systems excited by L\'evy white
noises. The proposed numerical procedure relies on the introduction of an
integral transform of Wiener-Hopf type into the equation governing the
characteristic function. Once this equation is rewritten as partial
integro-differential equation, it is then solved by applying the method of
convolution quadrature originally proposed by Lubich, here extended to deal
with this particular integral transform. The proposed approach is relevant for
two reasons: 1) Statistics of systems with several different drift terms can be
handled in an efficient way, independently from the kind of white noise; 2) The
particular form of Wiener-Hopf integral transform and its numerical evaluation,
both introduced in this study, are generalizations of fractional
integro-differential operators of potential type and Gr\"unwald-Letnikov
fractional derivatives, respectively.Comment: 20 pages, 5 figure
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Characterizing the strength of wood truss joints
Probability density functions (normal, lognormal, and three-parameter Weibull) were used to characterize strength data for three different types of metal-plate-connected wood truss joints (web at the bottom chord, tension splice, and heel). Modulus of elasticity (MOE) of the lumber used to fabricate the joints was also characterized. A probability-plot technique, in conjunction with Kolmogorov-Smirnov and chi-square statistics, was used to determine which distribution best fit the data. Lumber MOE was best described by a lognormal distribution. No single distributional form fit the strength data for all three joint types with equal accuracy. Lumber MOE and joint strength were unrelated. Strength data for the web at the bottom chord and heel joints were best described by normal distributions; however, none of the distributions considered fit the data for the tension splice joints. The probability-plot technique provided a better visual inspection of fit than did a density function superimposed over a histogram. Fitted distributions are easy to work with and can be used in reliability analyses to simulate strength values of joints. The results presented here are for particular joint types and plates and should not be extrapolated to other truss joints
Continuous professional development: elevating thoracic oncology education in Europe
The @EuroRespSoc launches a new thoracic oncology continuous professional development programme http://bit.ly/31ShuTp
Theory of the Relativistic Brownian Motion. The (1+1)-Dimensional Case
We construct a theory for the 1+1-dimensional Brownian motion in a viscous
medium, which is (i) consistent with Einstein's theory of special relativity,
and (ii) reduces to the standard Brownian motion in the Newtonian limit case.
In the first part of this work the classical Langevin equations of motion,
governing the nonrelativistic dynamics of a free Brownian particle in the
presence of a heat bath (white noise), are generalized in the framework of
special relativity. Subsequently, the corresponding relativistic Langevin
equations are discussed in the context of the generalized Ito (pre-point
discretization rule) vs. the Stratonovich (mid-point discretization rule)
dilemma: It is found that the relativistic Langevin equation in the
Haenggi-Klimontovich interpretation (with the post-point discretization rule)
is the only one that yields agreement with the relativistic Maxwell
distribution. Numerical results for the relativistic Langevin equation of a
free Brownian particle are presented.Comment: see cond-mat/0607082 for an improved theor
The DIAMORFOSIS (DIAgnosis and Management Of lung canceR and FibrOSIS) survey: international survey and call for consensus.
Background
Currently there is major lack of agreement on the diagnostic and therapeutic management of patients with idiopathic pulmonary fibrosis (IPF) and lung cancer. Our aim was to identify variations in diagnostic and management strategies across different institutions and provide rationale for a consensus statement on this issue.
Methods
This was a joint-survey by European Respiratory Society (ERS) Assemblies 8, 11 and 12. The survey consisted of 25 questions.
Results
Four hundred and ninety-four (n=494) physicians from 68 different countries and five continents responded to the survey. Ninety-four per cent of participants were pulmonologists, 1.8% thoracic surgeons and 1.9% oncologists; 97.7% were involved in multidisciplinary team approaches on diagnosis and management. Regular low-dose high-resolution computed tomography (HRCT) scan was used by 49.5% of the respondents to screen for lung cancer in IPF. Positron emission tomography (PET) scan and endobronchial ultrasound (EBUS) is performed by 60% and 88% to diagnose nodular lesions with mediastinal lymphadenopathy in patients with advanced and mild IPF, respectively. Eighty-three per cent of respondents continue anti-fibrotics following lung cancer diagnosis; safety precautions during surgical interventions including low tidal volume are applied by 67%. Stereotactic radiotherapy is used to treat patients with advanced IPF (diffusing capacity of the lung for carbon monoxide (DLCO) <35%) and otherwise operable nonsmall cell lung cancer (NSCLC) by 54% of respondents and doublet platinum regimens and immunotherapy for metastatic disease by 25% and 31.9%, respectively. Almost all participants (93%) replied that a consensus statement for the management of these patients is highly warranted.
Conclusion
The diagnosis and management of IPF-lung cancer (LC) is heterogeneous with most respondents calling for a consensus statement
The DIAMORFOSIS (DIAgnosis and Management Of lung canceR and FibrOSIS) survey. International survey and call for consensus
Background: Currently there is major lack of agreement on the diagnostic and therapeutic management of patients with idiopathic pulmonary fibrosis (IPF) and lung cancer. Our aim was to identify variations in diagnostic and management strategies across different institutions and provide rationale for a consensus statement on this issue. Methods: This was a joint-survey by European Respiratory Society (ERS) Assemblies 8, 11 and 12. The survey consisted of 25 questions. Results: Four hundred and ninety-four (n=494) physicians from 68 different countries and five continents responded to the survey. Ninety-four per cent of participants were pulmonologists, 1.8% thoracic surgeons and 1.9% oncologists; 97.7% were involved in multidisciplinary team approaches on diagnosis and management. Regular low-dose high-resolution computed tomography (HRCT) scan was used by 49.5% of the respondents to screen for lung cancer in IPF. Positron emission tomography (PET) scan and endobronchial ultrasound (EBUS) is performed by 60% and 88% to diagnose nodular lesions with mediastinal lymphadenopathy in patients with advanced and mild IPF, respectively. Eighty-three per cent of respondents continue anti-fibrotics following lung cancer diagnosis; safety precautions during surgical interventions including low tidal volume are applied by 67%. Stereotactic radiotherapy is used to treat patients with advanced IPF (diffusing capacity of the lung for carbon monoxide (D LCO) <35%) and otherwise operable nonsmall cell lung cancer (NSCLC) by 54% of respondents and doublet platinum regimens and immunotherapy for metastatic disease by 25% and 31.9%, respectively. Almost all participants (93%) replied that a consensus statement for the management of these patients is highly warranted. Conclusion: The diagnosis and management of IPF-lung cancer (LC) is heterogeneous with most respondents calling for a consensus statement
Extremal dependence between temperature and ozone over the continental US
The co-occurrence of heat waves and pollution events and the resulting high
mortality rates emphasize the importance of the co-occurrence of pollution
and temperature extremes. Through the use of extreme value theory and other
statistical methods, tropospheric surface ozone and temperature extremes and
their joint occurrence are analyzed over the United States during the summer
months (JJA) using measurements and simulations of the present and future
climate and chemistry. Five simulations from the Chemistry-Climate Model
Initiative (CCMI) reference experiment using specified dynamics (REFC1SD)
were analyzed: the CESM1 CAM4-chem, CHASER, CMAM, MOCAGE and MRI-ESM1r1
simulations. In addition, a 25-year present-day simulation branched off the
CCMI REFC2 simulation in the year 2000 and a 25-year future simulation
branched off the CCMI REFC2 simulation in 2100 were analyzed using CESM1
CAM4-chem. The last two simulations differed in their concentration of carbon
dioxide (representative of the years 2000 and 2100) but were otherwise
identical. In general, regions with relatively high ozone extremes over the
US do not occur in regions of relatively high temperature extremes. A new
metric, the spectral density, is developed to measure the joint extremal
dependence of ozone and temperature by evaluating the spectral dependence of
their extremes. While in many areas of the country ozone and temperature are
highly correlated overall, the correlation is significantly reduced when
examined on the higher end of the distributions. Measures of spectral density
are less than about 0.35 everywhere, suggesting that at most only about a
third of the time do extreme temperatures coincide with extreme ozone. Two
regions of the US have the strongest measured extreme dependence of ozone and
temperature: the northeast and the southeast. The simulated future increase
in temperature and ozone is primarily due to a shift in their distributions,
not to an increase in their extremes. The locations where the right-hand side
of the temperature distribution does increase (by up to 30 %) are
consistent with locations where soil–moisture feedback may be expected.
Future changes in the right-hand side of the ozone distribution range
regionally between +20 % and −10 %. The location of future increases
in the high-end tail of the ozone distribution are weakly related to those of
temperature with a correlation of 0.3. However, the regions where the
temperature extremes increase are not located where the extremes in ozone are
large, suggesting a muted ozone response.</p
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